-LRB- CNN -RRB- -- Theodore Wafer said he was sorry from the bottom of his heart Wednesday for gunning down an unarmed young woman on the front porch of his Michigan home , but a judge said `` mistake '' was the wrong word to describe a murder and sentenced him to 15 to 30 years in prison .

Wafer , 55 , looked down , his lawyer patting him on the back , as Wayne County Circuit Judge Dana Hathaway sentenced him for second-degree murder in the November shooting death of Renisha McBride , 19 -- a racially charged case because the victim was black and Wafer is white .

Wafer had testified that he feared for his life when loud banging startled him awake in the early morning hours of November 2 , 2013 . He opened his front door and fired a fatal shotgun blast into the face of McBride , who prosecutors say was seeking help after a car accident .

`` To the parents family and friends of Renisha McBride , I apologize from the bottom of my heart and I am truly sorry for your loss , '' Wafer said . `` I can only hope and pray that some how you can forgive me . ... From my fear , I caused the lost of a life that was too young to leave this world and for that I carry that guilt and sorrow forever . ''

Hathaway said it was one of the `` saddest cases '' she had ever presided over .

`` I do not believe that you are a cold-blood murderer or that this case had anything to do with race or that you are some sort of monster , '' the judge said . `` I do believe you acted out of some fear but mainly anger and panic and unjustified fear is never an excuse to take someone 's life . ''

Hathaway said she was confident Wafer was remorseful and would likely never commit another crime in his life , but that McBride came to his doorstep seeking help and lost her life .

`` You made the choices that brought us here , '' the judge said . `` I do n't know that you could ever use the word ` mistake ' to describe a murder , and a person was murdered . ''

The defense had argued for a sentence of four to seven years , saying a longer sentence guaranteed that he would never get out of prison alive .

But Hathaway said the sentencing guidelines were reasonable for the crime , giving him 15 to 30 years for second-degree murder and two additional years for possessing a firearm while committing the felony .

Before sentencing , Walter Simmons , McBride 's father , addressed the court .

`` This man has ruined our family 's life , '' he said `` There 's not a day that goes by that I do n't think about my daughter . ''

McBride 's sister , Jasmine , said : `` Losing my sister was one of the most devastating times of my life . Mr. Wafer , your actions impact a lot of other people other than just yourself . ''

After Wafer was convicted in August , McBride 's mother , Monica , described her daughter as a `` regular teenager '' who was `` well-raised and brought up with a loving family . ''

During his trial , Wafer testified feeling the floor vibrate under his feet from the violent pounding on his front and kitchen doors . He said he could n't find his cell phone to call 911 , but retrieved his Mossberg 12-gauge shotgun from a closet and opened the front door at a quiet moment .

`` I was not going to cower . I did n't want to be a victim in my own house , '' he said . `` I drew first , that 's how I see it . ''

McBride had a blood-alcohol level more than two times the legal limit at the time of her death and had smoked marijuana earlier in the evening , according to testimony .

Witnesses said she crashed her vehicle into a parked car in Dearborn Heights , Michigan , just before 1 a.m. and wandered off disoriented and bloodied . Some three hours later , she lay dead on Wafer 's porch .

The incident sparked protest and was likened by some to the shooting of unarmed Florida teen Trayvon Martin in 2012 .

After the incident , Wafer told police he was angry and `` full of piss and vinegar '' when he opened the door that night , according to prosecutors .

CNN 's Lena Jakobsson contributed to this report .

@highlight

Theodore Wafer sentenced to 15-30 years in prison for shooting teen on front porch

@highlight

Wafer said : `` I apologize from the bottom of my heart ''

@highlight

Judge : `` I do n't know that you could ever use the word ` mistake ' to describe a murder ''

@highlight

Prosecutors said McBride was seeking help after a car accident